Hemodialysis system



Filed March 15, 1966 J. -E. CARY ETAL HEMODIALYSIS SYSTEM 2 Sheets-Sheet 1 JAMES E. GARY HARVEY F. SWENSON #NVENTORS ATTORNEYS July 29,1969 ig, R ET AL 3,457,944

HEMODIALYSIS SYSTEM 2 Sheets-Sheet. 2

Filed March 15, 1966 m ON 0% AH J NH m8 CNN IIHHMHII'IIHIHI'I'IHF LIII'AII. Na 2N at? an wow wwu L V QF JAMES E. GARY HARVEY F. SWENSON ATTORNEYS U i ed States Patent 3,457,944 HEMODIALYSIS SYSTEM James E. Cary, Edmonds, and Harvey F. Swenson,

Seattle, Wash., assignors to Sweden Freezer Manufacturing (30., Seattle, Wash., a corporation of Washington Filed Mar. 15, 1966, Ser. No. 534,329 Int. Cl. F16k 49/00; F161 53/00 US. Cl. 137-341 8 Claims ABSTRACT OF THE DISCLOSURE This invention is a hemodialysis system and relates to the medico-engineering arts concerned with artificial kidney systems.

In recent years, artificial kidneys have been developed to treat patients with acute renal failure and to rehabilitate patients who would otherwise die of chronic uremia. One of the major problems in the use of artificial kidneys has been the complexity of the technique of hemodialysis. Apparatus associated with this technique heretofore could be operated and controlled only by highly trained personnel. Furthermore, such apparatus is quite bulky and very expensive and thus has found only limited use despite the pressing need for artificial kidneys.

As artificial kidney systems become less complex and expensive, such systems will be frequently used by patients at home rather than at a hospital or clinic. Consequently, apparatus must be provided that can be easily and safely operated by members of a patients family at home.

A primary object of this invention is to provide a hemodialysis system that can be operated and controlled safely by non-technically trained personnel. Another object is to provide a ready-to-use supply of dialysis solution without wasting any of such supply. A further object is to provide such a system wherein harmful bacteriological growth is greatly inhibited or even eliminated. Still another object of this invention is to provide such a system wherein manufacture of dialysis solution is easily and conveniently accomplished. A still further object is to provide such a system wherein a portion of the patients blood need not be cooled to minimize bacteria growth. Still another object is to provide such a system wherein the dialysis solution is discarded after a single use thereby greatly minimizing contamination problems, and increasing dialysis efficiency.

These and other objects and advantages will become apparent from the following description in conjunction with the accompanying drawings, of which:

FIG. 1 is a perspective view of a dialysis solution storage means with certain portions broken away;

FIG. 2 is a schematic diagram of the system of the invention; I

FIG. 3 is a schematic diagram of a dialysis station for use with the dialysis solution storage means of this invention; and

FIG. 4 is an exemplary control panel for use with the dialysis solution storage means of this invention.

The dialysis system of this invention comprises an automatic, self-contained system for manufacturing dialysis solution from premeasured chemicals and an ac- Tee ceptable water supply for distribution to a dialyzer at a bedside station. Several solenoid-operated control valve means are provided to permit automatic operation of the system.

More particularly, the invention comprises a central dialysis solution storage means, a diaylsate concentrate supply means, means for supplying controlled temperature water to the storage means, and means for supplying dialysis solution to a dialyzer station. The dialysis solution storage means, dialysate concentrate supply means and water supply means may constitute a central unit located in an out-of-the-way part of a patients home, and'the dialyzer station may constitute a separate unit located at a patients bedside and connected to the central unit by the dialysis solution supply means.

In regard to FIGS. 1 and 2, a preferred central unit comprises a dialysis solution storage means 110, a dialysate concentrate supply means 112, means 114 for supplying controlled temperature water to the storage means 110, and means 116 for supplying dialysis solution to a dialyzer station.

The dialysis solution storage means comprises a thermally-insulated dialysis solution mixing and storage tank 118 having a closeable inspection opening on the top and a liquid inlet near the tank bottom and a liquid outlet at the tank bottom, heating means 120 positioned near the bottom of the tank 118, a liquid sprayer means 122 positioned near the bottom of the tank 118, liquid level indicators 5, 6 and 7 located within the tank 118, and an immersion-type temperature sensor located near the bottom of the tank 118.

The liquid level indicators may be fixed in place, or they may be float-actuated microswitches as depicted in FIG. 1. As shown in FIG. 1, these liquid level indicators comprise floats 124a and 126a slidably mounted on a vertical float rod 111 adjacent to an inner surface of the tank side wall, a float 128a slidably mounted on a vertical float rod 113 adjacent to an inner surface of the tank side wall, and corresponding magnetic float-actuated microswitches 124b, 1261) and 12% mounted adjacent the outer surface of the tank side wall in proximity to the floats. The floats are fabricated in the form of hollow annuli which are carried along their respective float rods by a rising or falling liquid level within the tank and which include ferrous material. Bumper members 11a and 113a are positioned on the float rods 111 and 113, respectively, such that the floats 124a and 128a cannot be carried upward past their respective microswitches. Each microswitch is activated when its respective float rises adjacent the switch magnet 124c, 126c or 1280. Because of the hollow annular shape of the floats 124a and 128a, they will remain buoyant as the liquid level rises above the elevation of their respective switches and will therefore remain in close proximity to their switches. The high level switch T2611 is vertically adjustable such that the upper fill limit of the tank can be varied from just above the level of the switch 124b to the maximum capacity of the tank. The function of indicators 5, 6 and 7 will be described subsequently.

Sprayer means 122 comprises a spray head 132 having two oppositely-oriented spray arms with end nozzles adapted to spray liquid against the entire inner surface of the tank, and an inlet conduit 134 connecting to the spray head. The spray head revolves when liquid is passed through the spray arms and nozzles.

Heating means 120 comprises a resistance heating element 136 which extends across the bottom of the tank and through one of the tank side walls, and a control element 138 mounted on the tank wall which controls the heating element. The function of the heating element will be described subsequently.

Dialysate concentrate supply means 112 comprises a reservoir tank 140 having a closeable top access opening and an outlet, a conduit 142 interconnecting the reservoir tank outlet and the storage tank 118, and a solenoidoperated control valve means 4 in the conduit which can be closed when a dialysate concentrate is to be placed within the reservoir tank and which can be opened to permit dialysate to flow by gravity into the storage tank 118.

Water supply means 114 comprises a conduit 144 connecting to the inlet to storage tank 118, a solenoid-operated control valve means 1 for controlling water flow through conduit 144, a solenoid-operated control valve means 2 for controlling hot water flow to conduit 144, and a solenoid-operated control valve means 3 for controlling fiow of controlled temperature water to conduit 144, which is derived by mixing hot water and cold water within the valve means 3.

Supply means 116 comprises a pump 146 having an inlet connected to the outlet to storage tank 118 by a conduit 148 and having an outlet connected to a solenoidoperated dialysis solution flow control valve means 8 by a conduit 150, and a sprayer by-pass conduit 152 connecting the pump outlet via conduit 150 to the sprayer inlet conduit 134. If desired, a solenoid-operated by-pass control means 10 may be provided in by-pass conduit 152 to control liquid flow therethrough. The pump outlet is also connected to a solenoid-operated drain valve means 9 by a conduit 154 for draining the central unit. Conduit 156 extends from valve means 8 to a dialysis station to transfer dialysis solution thereto.

The bedside station will deliver dialysis solution to a dialyzer such as a Kil-type dialyzer, within a manuallyadjustable pressure of from atmosphere to 150 millimeters negative pressure across the dialyzer. When adjusted, the station will control the setting within i1 millimeter. A control automatically shuts oi? the negative pressure pumping and dialysis solution flow it: the solution supply is interrupted, the negative pressure exceeds 150 millimeters, or the'solution temperature exceeds 106 F. The bedside station includes a dialysis solution reservoir tank vented to atmosphere so that maximum pressure delivered to the dialyzer is static head pressure. Dialysis solution flow is indicated by a flow meter and dialysis solution temperature is indicated by a thermometer. Automatic tempering of dialysis solution is provided. Negative pressure is monitored by a mercury manometer and regulated by a manual valve.

As shown in FIG. 3, a preferred bedside station 200 comprises a reservoir tank 202 with a dialysis solution inlet 94 connected to supply conduit 156, a vent and overflow conduit 204, and a dialyzer supply conduit 206. Dialyzer supply conduit 206 connects to the inlet of a dialyzer 208 through a quick disconnect coupler 210. A waste conduit 212 connects the outlet of dialyzer 208 to a positive displacement pumping means 214, a manuallyoperable shutoff valve 216 and a flow metering means 218. A manometer pressure sensing means 220 is connected to waste conduit 212 and is adapted to stop dialysis if a negative pressure greater than about 150 mm./Hg is sensed.

Reservoir tank 202 is provided with a heating means 222 that is manually adjustable to temper the dialysis solution within reservoir tank 202 for patient comfort, e.g. to 98 F., and to hold temperature settings within a reasonable range, for example :2 F. Temperature sensor 224 and a high temperature switch 226 are set to stop dialysis if the dialysis solution reaches an unac ceptably high temperature on the order of 106 F. The reservoir tank 202 is also provided with a dialysis solution valve control means 228 comprising a float-controlled inlet valve 230 which prevents overfilling, and a dry float switch 232 which stops dialysis if the quantity of dialysis solution in reservoir tank 202 falls below a predetermined minimum level.

Dialysis solution supply conduit 206 is provided with a manually adjustable negative pressure valve 234 to control pressure of the dialysis solution being drawn through the dialyzer 208 by pumping means 214. If desired, a solenoid-operated control valve means 236 may also be provided in conduit 206 to control dialysis solution flow to the dialyzer 208.

Waste conduit means 212 connects to the outlet to dialyzer 208 through a quick disconnect coupler 238. A sterilizing connector 240 is provided and adapted to receive couplers 210 and 238 to bypass dialyzer 20 8 when the bedside station is to be sterilized. Connector 240 includes a sterilize switch means 242 which is actuated when couplers 210 and 238 are attached to connector 240 as indicated by broken lines in FIG. 3 and which shuts off control circuitry associated with manometer 220, high temperature switch 226, and alters circuitry associated with float means 228 so that high temperature sterilizing Water can be drawn through the bedside station by pumping means 214 without automatically shutting down pumping means 214. If high temperature sterilizing water is inadvertently passed to the bedside station without connecting couplers 210 and 238 to bypass dialyzer 208, high temperature switch 226- would automatically shut otf pumping means 214 and close solenoid-operated control valve means 236 (if provided) to stop dialysis.

The connecting tube 244 for the manometer sensing means 220 is disconnected from waste conduit 212 at a port in coupler 238 and then this port is sealed with plug means 260 (conveniently hung on a chain) so that the manometer will be disconnected when coupler 238 is attached to connector 240 for sterilizing. One leg of the manometer is so connected at coupler 238 through pressure line 244 and contains electrical contacts 246 which are electrically connected when mercury rises to cover the contacts 246 at a negative pressure greater than about 150 mm./Hg to inactivate pumping means 214 and close solenoid-operated control valve means 236 (if provided) and thereby stop dialysis. The other leg of the manometer is open to atmosphere.

The system of this invention has a rinse and sterilizing cycle, a filling cycle, and a dialyzing cycle. With reference to the figures and to Table I an exemplary operation of these cycles is as follows.

TABLE I.TIME CYCLES FOR 100 GAL. CAPACITY SYSTEM Components 8 2 1 9 11 12 146 100 Minutes Power Timer Control valves Pump Heat;

10% min. rinse:

14 0n 0n Ope11.. Open.... Open. Open 011.... 15 4, 011 Off 24%.. 35 min. sterilize:

011...... Off..

(Closed by 7) TABLE IContintled Components 1 3 11 13 Fill 98 146 Minutes Power switch Control valves Heat Pump 25 min. (100 gal.) fill:

On. On Open Open On On.

6 closes l and 3.

Components 11 13 Dialyze 8 Control 146 98 Power switch valve Pump Heat Dlalyze On On Open On On 01? Ofi Off Off switch on if necessary.

Components 11 14 Drain 146 9 Control Power switch Pump valve Drain On 0n On Open.

011 Ofi Otl Ofi.

Time, whatever amount is in tank.

146 will shut ofi and 9 will close.

All components it not on chart are to be assumed off or closed.

To rinse and sterilize the system, power switch 11, which is a two-position toggle, is switched on, and the timer switch 12 is set thereby programming the rinse and sterilize cycle. Control valve means 1, 2 and 8 (and 10 if provided) are opened to permit hot rinse water (about 140 F.) to flow into storage tank 118 until liquid level indicator 7 is actuated by float 128a rising in proximity to microswitch 128b, Actuation of liquid level indicator 7 causes control valve means 1 and 2 to close thereby terminating the filling of storage tank 118. Pump 146 is turned on to pump the rinse water from storage tank 118 indicator 7 being deactivated by float 128a falling away from microswitch 12811 as the rinse fluid is drained from the storage tank. Control valve means 1 and 2 are then opened to permit hot water (about 140 F.) to again flow into the storage tank until the water level rises sufficiently to actuate liquid level indicator 7. Pump 146 is then turned on (and control valve means 10, if provided is opened to pump hot water through liquid sprayer means 122 and to the dialysis station. Heating means 120 is then actuated to heat the Water in the storage tank to a sterilizing temperature of about 190 F. and the sterilizing water continues to be pumped through the liquid sprayer means and to the dialysis station. The heating means is then deactivated, and control valve means 9 opened (and control valve means 10 closed, it provided) and the sterilizing water drained from the system. The timer switch 12 now has completed its course and the electrical control system is shut down.

To fill the storage tank, the power switch 11 is switched on, a switch 13, a three-position toggle, is turned to the fill position thereby programming the fill cycle. Control valve means 1 and 3 are turned on to fill the storage tank with warm water (about 98 F.) and 'then heating means 120 is actuated to maintain the water temperature at about 980 F. Pump 146 is then turned on (and control valve means 10 is opened, if provided) to circulate water through liquid sprayer means 122. Control valve means 4 is then opened to empty dialysate concentrate into the storage tank to form the dialysis solution. When 20 seconds after level drops past 7,

the water level rises to activate liquid level indicator 6 by float 126a rising in proximity to microswitch 126b, control valve means 1 and 3 are deactivated thereby terminating water flow into the storage tank. The system is now ready for dialysis. If switch 13 is turned to the cit position, pump 146 will stop but the heating means will remain actuated. Heating means will remain actuated unless the liquid level in the storage tank falls below liquid level indicator 7, thereby deactuating it.

To dialyze, the power switch 11 is turned on, and the switch 13 is switched to the dialyze" position thereby programming the dialyze cycle. Control valve means 8 is opened and pump 146 turned on to pump dialysis solution to the dialysis station. It the solution level in the storage tank falls below the liquid level indicator 7, the heating means will be deactuated.

To drain, the power switch 11 is turned on and a switch 14, a momentary toggle, is switched to drain thereby programming the drain cycle. The pump is turned on and control valve means 9 is opened to drain the storage tank contents. The pump is stopped and control valve means 9 closed by time delay action resulting from liquid level indicator 7 being deactuated by the solution level falling below it. The drain cycle can be operated concurrently with the dialyze cycle or independently of the latter.

What is claimed is:

1. A dialysis solution storage system which comprises a dialysis solution storage means; a dialysate concentrate supply means adapted to supply dialysate concentrate to said dialysis solution storage means; means for supplying controlled temperature water to said dialysis solution storage means for mixture with dialysate concentrate to provide a dialysis solution; and means for supplying dialysis solution from said dialysis solution storage means to a dialyzer station.

2. A system according to claim 1 wherein said dialysis solution storage means includes a dialysis solution mixing and storage tank; and liquid level indicating means comprising first and second vertical float rods positioned adjacent to the tank inner surface, a first float slidably mounted on the first rod, a first bumper mounted on said first rod to limit upward movement of said first float, a second float slidably mounted on said first rod above said first bumper, a third float slidably mounted on the second rod, a second bumper mounted on said second rod to limit upward movement of said third float, and first, second and third switch means mounted exteriorly to said tank adjacent to the respective first, second and third floats for actuation by the respective floats; said first switch means preventing actuation of said heating means when the tank liquid level falls below the elevation of said first switch means, said second switch means preventing water supply to said tank when the tank liquid level rises to the elevation of said second switch means, and said third switch means preventing actuation of said dialysis solution supply means when the tank liquid level falls below a predetermined elevation.

3. A system according to claim 1 wherein said dialysis solution storage means includes a dialysis solution mixing and storage tank; and sprayer means comprising a spray head having two oppositely orientedspray arms with end nozzles adapted to spray liquid against the tank inner surface, and a sprayer inlet conduit extending into said tank and communicating with said dialysis solution supply means and with said spray head to recirculate solution from said storage means through said spray head, said spray head being adapted to revolve as liquid passes through the spray arm and nozzle.

4. A system according to claim 1 wherein said storage means comprises a dialysis solution mixing and storage tank having a water inlet near the bottom thereof communicable with said water supply means, a liquid outlet at the bottom thereof communicable with the dialyzer means for controlling fiow of controlled temperature water to said water inlet conduit.

7. A system according to claim 4 wherein the dialysis solution supply means comprises pumping means having an inlet communicating with the tank liquid outlet and an outlet, control valve means communicating with the pumping means outlet, and a sprayer by-pass conduit interconnecting said pumping means outlet and a sprayer inlet conduit within said dialysis solution storage means; and wherein said liquid spraying means comprises a spray head and a sprayer inlet conduit.

8. A dialysis system which comprises a dialysis solution storage system comprising a dialysis solution storage means, a dialysate concentrate supply means adapted to supply dialysate concentrate to said dialysis solution storage means, means for supplying controlled temperature water to said dialysis solution storage means for mixture with dialysate concentrate to provide a dialysis solution, said water supply means being selectively operable to supply rinse and sterilizing water to said dialysis solution storage means, and means for supplying liquid from said dialysis solution storage means to a dialyzer station; and a dialyzer station comprising reservoir means for receiving liquid from said dialysis solution storage means, a

' dialyzer supply conduit extending from said reservoir means and communicable with an inlet to a dialyzer,

station supply means, and a dialysate concentrate inlet communicable with said dialysate concentrate supply means; heating means positioned near the tank bottom to maintain a desired dialysis solution temperature; liquid sprayer means positioned near said tank bottom and communicable with said dialysis station supply means to recirculate liquid from said liquid outlet back into said tank; liquid level indicating means for sensing liquid level in said tank; and temperature sensing means for sensing the temperature in said tank.

5. A system according to claim 4 wherein said dialysate concentrate supply means comprises a reservoir tank having a closable access opening and an outlet; a conduit interconnecting the reservoir tank outlet and the mixing and storage tank dialysate concentrate inlet; and control valve means for controlling dialysate concentrate transfer from said reservoir tank to the mixing and storage tank.

6. A system according to claim 4 wherein the water supply means comprises a water inlet conduit connected to the tank water inlet; first control valve means for controlling water flow through said water inlet conduit; second control valve means for controlling fiowof hot water to said water inlet conduit; third control valve pumping means, a waste conduit extending from said pumping means and communicable with an outlet to a dialyzer, and sterilizing connection means adapted to detachably couple said dialyzer supply conduit to said waste conduit to bypass the dialyzer when rinse and sterilizing liquid is supplied from said dialysis solution storage means.

References Cited UNITED STATES PATENTS 2,155,273 4/1939 Jones. 2,411,239 11/1946 Reichel et al 210--321 2,720,879 10/1955 Gasca et al. 210-22 XR 2,880,501 4/1959 Metz 210--321XR 2,969,150 1/1961 Broman 210-321 3,158,160 11/1964 Estandian 134-176 XR 3,072,259 1/ 1963 Isreeli 210321 XR 3,285,779 11/1966 Dunham 134176 XR SAMUEL SCOTT, Primary Examiner US. Cl. X.R. 210321 

